1. Field of the Invention
The present invention relates to an apparatus for testing a semiconductor memory, and in particular to an apparatus for testing a semiconductor memory which is capable of implementing an accurate operation state under a real mounting environment of a memory device by varying a voltage applied to a memory device which will be tested using a main board of a computer system such as a PC, a net station computer, a server computer, etc.
2. Description of the Background Art
Generally, in an apparatus using a semiconductor memory such as a SDRAM(Synchrous Dynamic Random Access Memory), a RAMBUS DRAM, or a SRAM(Static Random Access Memory), in order to check the characteristic or reliability of an interior circuit after an assembling operation of a device, an assembled device is mounted in a socket, and then the test is performed using a specific equipment for an expensive semiconductor memory test.
However, since the semiconductor memory test apparatus is expensive, the cost for a test of one memory device is increased. Therefore, the product competitive capacity of a company is decreased. In addition, since the memory device is tested using an additional apparatus, not under an actual environment, it is impossible to implement a desired use environment characteristic in a PC main board which is an actual environment for using a memory device.
In order to overcome the above problems, in a semiconductor device fabrication field, recently, a test method using a main board of a computer apparatus such as a PC, a work station or a server which actually uses a semiconductor device is generally used.
In the method using a main board of a computer apparatus, a socket is used for detachably installing a memory module or a unit semiconductor device on a main board. The memory module or unit memory device which will be tested is inserted into the socket, and then the computer apparatus is operated, so that it is possible to test whether the semiconductor device is defective or not.
However, in the above-described method, a voltage(for example, 3V) supplied from a power supply unit of a computer apparatus is directly supplied to a semiconductor memory device(module) which will be tested. The accuracy of the test is decreased under an actual operation environment. Namely, in the case that the voltage supplied thereto is changed, the result of the test may be changed.